Flush-mounted panel assembly

Abstract: A flush-mounted articulated window assembly for use in a vehicle is adapted to be mounted in a window opening such that, when closed, it is generally flush with the exterior surface of the vehicle. The window assembly includes a transparent sheet with at least one window-mounting member (30) bonded by two separate adhesives to an inner surface of the sheet. The mounting member includes projections which space the mounting member from the inner sheet surface, and/or perforations which allow air and moisture to reach the space provided between the mounting member and the inner sheet surface. A first adhesive temporarily fixtures the mounting member to the sheet. A second adhesive permanently bonds the mounting member to the inner sheet surface. The bond created is sufficiently strong such that application of a load sufficient to cause a failure results in a failure other than in the adhesion of the adhesive to the mounting member and the panel.

Description: This invention relates generally to flush-mounted window assemblies for, for example, vehicles and more particularly, to flush-mounted vehicular window assemblies which articulate about a hinge attached to one side of the window in a manner to achieve long-term reliability. In an effort to make automobiles more fuel-efficient, automobile exterior designs are becoming more streamlined. In pursuit of this automobile manufacturers are requiring flush-mounted panel and window assemblies. The goal is to locate the panel or window within the vehicle such that the peripheral edge of the panel or window assembly is recessed and the outer surface of the panel is generally flush with any adjoining body panels. In the case of fixed panels, a conventional technique includes placing or running a bead of adhesive material around the entire inside peripheral edge of the panel and bonding it in the vehicle opening. While satisfactory for stationary windows, this method creates problems with movable windows, however, particularly those which articulate about a hinge. Conventional articulated or hinged windows are fixed to the vehicle by a mounting assembly which is fastened by a stud passing through a hole drilled in the panel. A low profile nut is then threaded onto the stud extending through the panel to retain the panel thereon. A major disadvantage is that a significant number of glass panels are broken as a result of drilling the holes through the panel. The panels are also broken during or after mounting of the mounting hardware. To lessen the incidence of broken glass panels, sophisticated techniques have been adopted for drilling the holes, and the mounting hardware has been adapted to reduce breakage. However, the price of such panel assemblies is still considerably inflated. Moreover, the resulting panel is not truly flush since the mounting hardware has a positive relief with respect to the panel exterior surface. Another attempt to reduce the exterior profile of articulated window assemblies is disclosed in U.S. Patent 4,396,221 which employs a channel extending around the edge of the window pane, a flexible resilient portion allowing pivotal movement of the window pane, and one of several types of fasteners. Such fasteners include a clip with a detent received in the seal and securing the hinge and thus the assembly to a pinch weld flange. Another embodiment of the hinged window assembly just described includes a substantially rectilinear hinge member which includes a retaining end bonded to the exterior or front surface of the window panel by an adhesive and an opposing retaining end having an aperture which receives a metal screw extending into the vehicle body. Seated on the pinch-weld flange is a sealing weather strip which forms a closed bulbous portion engaging both the inside surface of the pane as well as a shoulder of the recess leading to the pinch weld flange on the exterior sheet metal body portion. To conceal the fastener for the hinge, a metal covering extending from the vehicle roof or another portion of the vehicle may extend over the fastener and a substantial portion of the hinge. A disadvantage associated with each of the above hinged windows is that the hinge member is fixed to the exterior surface of the panel. In addition, in the last embodiment described above, the fastener securing the assembly to the vehicle is exposed, or must include a special cover member. Accordingly, the exterior profile of these window assemblies do not result in a truly flush-mounted, articulated window assembly. Although it is known in the art to adhesively bond metal to glass for a variety of purposes such as stud attachments, small hinge plates, etc., known hinge adhesives and hinge designs are inadequate to meet load requirements and long-term environmental resilience required for flush-mounted, hinged window assemblies. Hinge mounting of large size, flush-mounted panels in the nature of van windows is a demanding application of adhesive technology. The greater weight of such a window transmits more severe vibration requiring greater strength and greater long-term environmental resilience and durability than is available with such prior known bonds. Styling and design limitations restrict the number of hinges and the size of the bond areas. EP-A-0,289,156 shows a panel assembly for a vehicle having the features set out in the precharacterising portion of claim 1. Accordingly, there is now a need for large panels such as van or tailgate windows having a flush mounted hinge, and an improved bond between a hinge member and the single panel surface to which it is attached to support the panel. The invention is defined in claim 1 and preferable features are recited in the claims dependent thereon. The panel assembly of this invention is especially useful as a flush-mounted vehicle window assembly, and includes, in combination, a panel having inner and outer surfaces which terminate in a peripheral edge and give the panel a predetermined geometric shape. At least one mounting member is secured to the inner surface of the panel and spaced from the peripheral edge. An adhesive is used to bond a flange of the mounting member to the inner surface of the panel. The resulting bond between the mounting member flange and the panel is sufficiently strong such that when a load sufficient to induce failure is imposed between the mounting member and the panel, failure of the panel assembly results other than in the adhesion of the adhesive to the mounting member or panel. More specifically, failure may occur as cohesive failure of the adhesive, mechanical failure of the mounting member adjacent the adhesive, or mechanical failure of the panel adjacent the adhesive. The bond is preferably strong enough to withstand a failure load of at least 68 kg (150 lb). According to one aspect of the invention there is provided a flush-mounted window assembly for a vehicle, comprising: a window panel having an inner and outer surface terminating in a peripheral edge; at least one mounting member secured to said inner surface and spaced from said peripheral edge, said mounting member having a flange attached to said inner surface; and an adhesive providing a bond between said flange of said mounting member and said inner surface of said panel, said bond being sufficiently strong such that when a load sufficient to induce failure is imposed between said mounting member and said panel, failure of said panel assembly results in other than the adhesion of said adhesive to said mounting member and said panel. According to another aspect of the invention there is provided a hinged window assembly for use in a vehicle, the window assembly adapted to be mounted in a window opening and generally flush with the exterior surface of the vehicle, comprising in combination: a transparent sheet having an inner and outer surface terminating in a peripheral edge defining a shape to fit within the window opening such that said outer surface of said sheet is generally flush with the exterior surface of the vehicle adjacent the opening; at least one window-mounting member bonded to said inner surface of said sheet at a position spaced inwardly from said peripheral edge for fixing said sheet in the window opening; and an adhesive, between said inner surface of said sheet and said mounting member, for bonding said sheet and mounting member together in such a manner so as to withstand a straight pull test of more than about 150 pounds. According to a further aspect of the invention there is provided a hinged window assembly for a window opening, comprising: a window panel having inner and outer surfaces and a peripheral edge defining a shape to fit within the window opening with said outer surface of said panel being generally flush with an outer surface of the window opening; at least one hinge having a flange portion located on said inner surface of said panel inwardly from said peripheral edge, and a hinge portion to engage the window opening; at least one latch mount having a base portion located on said inner surface of said panel inwardly from said peripheral edge and spaced from the hinge assembly, said latch mount having an end portion to be attached to an inside of the window opening; a first adhesive for temporarily fixturing said hinge assembly and said latch mount on said inner surface of said panel and having a first cure/set time; and a second adhesive disposed in the space between said inner surface of said panel and said hinge and latch mount for permanently bonding said hinge and latch mount to said inner surface of said panel and having a second cure/set time greater than said first cure/set time. In one form the invention is a hinged vehicle window, comprising: a sheet-like window panel having first and second opposing surfaces and a peripheral edge; at least one hinge having a flange adjacent the first surface of the panel and a hinge portion extending from the flange, said flange having a plurality of perforations extending therethrough, and a plurality of standoffs for spacing said flange from said panel; and an adhesive between said flange and said first surface of said panel for bonding said flange to said panel so that said panel is supported by said hinge. In a particular form of the invention an articulated vehicle window for use in a vehicle opening, comprises in combination: a transparent sheet of glass having inner and outer surface terminating in a peripheral edge defining a shape to fit within the window opening of the vehicle such that said outer surface of said glass is generally flush with the exterior surface of the vehicle adjacent the opening; an opaque frit layer deposited on, and bonded to, a predetermined portion of said inner surface of said glass; a pair of hinges generally aligned with each other and mounted on said inner surface of said glass on said frit layer, and spaced inwardly from said peripheral edge of said glass for fixing one end of said glass in the vehicle opening, each hinge having a plurality of projections extending from a hinge portion adjacent the inner surface of the glass for spacing said hinge from said inner surface of said glass, said hinge portion further having a plurality of holes for allowing air and moisture to pass therethrough; a latch mount attached to said inner surface of said glass on said frit layer and spaced inwardly from said peripheral edge and distant from said pair of hinges, for receiving a latching mechanism for moving said glass between an open and closed position with respect to the vehicle opening, said latch mount having a plurality of projections extending therefrom for spacing said latch mount from said inner surface of said glass, and a plurality of holes extending through said latch mount to allow air and moisture to pass therethrough; a first adhesive for temporarily fixturing said pair of hinges and said latch mount to said inner surface of said glass on said frit layer and having a first set/cure rate; and a second adhesive for permanently bonding said pair of hinges and said latch mount to said inner surface of said glass on said frit layer and having a second set/cure rate greater than said first adhesive. In another particular form of the invention an articulated window assembly for use in a vehicle, comprises: a window panel having inner and outer surfaces terminating in a peripheral edge; at least one articulated mounting member secured to said inner surface and spaced from said peripheral edge, said mounting member including a flange attached to said inner surface of said window panel; and an adhesive bonding said flange of said mounting member to said inner surface of said window panel, a bond created by said adhesive able to withstand a load up to 150 pounds; wherein said flange of said mounting member occupies approximately between 0.5 percent and 2.0 percent of a surface area of said window panel inner surface. One embodiment of the invention includes an articulated window assembly for use in a vehicle wherein the window assembly is mounted in the window opening from the inner surface with the opposite surface generally flush with the exterior surface of the vehicle. The articulated window assembly includes, in combination, a transparent sheet having inner and outer surfaces terminating in a peripheral edge and defining a shape to fit within the window opening. At least one window-mounting member is bonded to the inner surface of the sheet at a position spaced inwardly from the peripheral edge and fixing the sheet in the window opening. The mounting member may include a plurality of projections extending therefrom for spacing the mounting member from the inner surface of the sheet by a predetermined distance. One or more adhesives are provided between the inner surface of the sheet and the mounting member for bonding the sheet and mounting member together in such a manner that when tested under a straight pull test of more than 150 pounds applied at a rate greater than 25 millimetres per minute, failure will occur generally in the sheet, the mounting member or the cohesiveness of the adhesive will fail, but the adhesion of the adhesive to the sheet or mounting member will not fail. Such strength is also maintained after soaking in 80°C water for at least 100 hours. Another embodiment of the invention includes a hinged window panel having a shape to fit within the window opening of a vehicle with an outer surface of the peripheral edge aligned generally flush with an outer surface of the window opening. At least one hinge assembly includes a flange portion which is located on the inner surface of the panel inwardly from the peripheral edge and a hinged portion for engaging the window opening. At least one latch-mounting member is provided having a base portion located on the inner surface of the panel inwardly from the peripheral edge and spaced from the hinge assembly. The latch-mounting member also includes an end portion to receive a latch interconnected to the inside of the window opening. A first adhesive is optionally provided having a quick setup time, for temporarily fixturing the hinge assembly and the latch-mounting member to the inner surface of the panel. A second adhesive is then provided for permanently bonding the hinge assembly and latch member to the inner surface of the panel and has a set-up or cure time greater than the first adhesive. According to additional aspects of the invention, the panel or transparent sheet may further include an opaque coating such as a ceramic frit between the inner surface of the panel and the adhesive bonding the mounting member, hinge or latch member, to the panel. An adhesion-promoting compound may also be applied to the opaque coating, mounting member, hinge or latch-mounting member, to enhance the bond with the adhesive. The panel assemblies of this invention have advantages over the prior art in that the mounting members do not need to be fixed by holes drilled through the panel yet provide a strong and resilient bond between the panel and the vehicle. Another advantage is that the mounting members no longer wrap around the exterior edge of the window panel or are exposed on the exterior of the window panel. Moreover, the panel assembly of this invention may be manufactured rapidly without complex machines, and is highly adapted for support of larger sized, heavier windows in vehicles in which significant vibration is encountered. Because the mounting members are fixed to the panel by an adhesive, fewer panels are broken during the manufacturing process. A still further advantage of the panel assembly of this invention is that the mounting members do not extend through and protrude from the panel, but are concealed on the inner surface of the panel which results in a flush, more streamlined and aesthetically pleasing panel assembly appearance. The above advantages, purposes and other features of the invention will become apparent from a study of the following detailed description of some exemplary embodiments taken in conjunction with the appended drawings, in which: Fig. 1 is a fragmentary perspective view of the articulated panel assembly of this invention mounted as a side window in a vehicle; Fig. 2 is a side elevational view of an exterior surface of the articulated panel assembly of Fig. 1; Fig. 3 is a side elevational view of the opposite, inner surface of the articulated panel assembly shown in Fig. 2; Fig. 4 is a plan view of one embodiment of a hinge mounted on the panel of Figs. 1-3; Fig. 5 is a fragmentary sectional view of the panel and hinge taken along line V-V in Fig. 4; Fig. 6 is a fragmentary sectional view of the panel and hinge taken along line VI-VI in Fig. 4; Fig. 7 is a fragmentary plan view of one embodiment of a mounting stud for use in association with a latching mechanism, the stud being mounted on the panel assembly of Figs. 1-3; Fig. 8 is a fragmentary sectional view of the panel assembly and mounting stud taken along line VIII-VIII in Fig. 7; Fig. 8A is a fragmentary sectional view of the panel assembly and mounting stud taken along line VIIIA-VIIIA in Fig. 8; Fig. 9 is a fragmentary sectional view of the panel assembly in a closed position on a vehicle and taken along line IX-IX in Fig. 1; Fig. 10 is a fragmentary sectional view of the panel assembly on a vehicle and taken along line X-X in Fig. 1; Fig. 11 is a fragmentary sectional view of the panel assembly on a vehicle and taken along line XI-XI in Fig. 1; Fig. 12 is a fragmentary sectional view of the panel assembly on a vehicle and taken along line XII-XII in Fig. 1; Fig. 13 is a fragmentary plan view of another embodiment of a hinge adapted for mounting on the panel of Figs. 1-3; Fig. 14 is a fragmentary sectional view of the panel and hinge taken along line XIV-XIV in Fig. 13; and Fig. 15 is a fragmentary sectional view of the hinge of Figs. 13 and 14 taken along line XV-XV in Fig. 13. Although this invention relates to flush-mounted articulated window panels for vehicles, the advantages of this invention are best realized in large flush-mounted articulated window panels such as used in side windows for vans, rear lift gate windows for vans, station wagons, utility vehicles, and trucks, and other vehicles such as aeronautical, nautical, rail, and other forms of transportation, which exert substantial loads on the bonds between the mounting hardware and the window panel. Such window panels have surface areas typically greater than 1613 cm 2 (250 in 2 ). Referring now to the drawings in greater detail, a panel assembly 12 is disposed on a vehicle 10 within a window opening 14 formed in the vehicle exterior 16. The panel or window assembly 12 is adapted to articulate or pivot about a pair of mounting members 30 (Figs. 3-6) positioned proximate a peripheral edge 18 of an inner surface 22. Panel assembly 12 is opened or closed about mounting members 30 by a second mounting member 32 (Figs. 2-3) interconnecting the vehicle 10 to a second portion of panel assembly 12 distant and spaced from mounting members 30. Although panel assembly 12 is shown pivoting about an axis proximate the leading peripheral edge 18, it is contemplated that this invention may also be used to articulate panels such as a rear window or tailgate window about a horizontal axis as well. In one embodiment, panel assembly 12 includes a panel or sheet 24 having outer and inner surfaces 20, 22, respectively. Panel 24 is preferably transparent glass which may be tempered, laminated, or otherwise strengthened using conventional techniques and principles. Panel 24 may be curved, bent or generally planar, having two substantially parallel sides, surfaces, or faces 20, 22 terminating in a peripheral edge 18 forming a panel having a predetermined geometric shape. Although transparent glass is preferred, other sheet-like panel materials may also be used, such as opaque or coated glass, transparent coated or opaque plastic materials, or multi-composite laminates, such as transparent glass and plastic. Optionally and preferably, deposited on and bonded to surface 22 of panel 24 is an opaque, and preferably black frit layer 26, and most preferably, a ceramic frit layer or coating covering and concealing a region of surface 22 from peripheral edge 18 inward. Alternatively, frit layer 26 may cover all or substantially all of surface 22. Usually, however, frit layer 26 conceals a continuous peripheral strip of surface 22 near edge 18, such as 5.1 cm (2 in) in from edge 18, as shown in Figs. 2 and 3. Glass panel 24, which is initially in an untempered condition after cutting and sizing to its desired shape, can be painted by screen coating or other techniques, with a coating of dark ceramic paint on its inner surface 22. Thereafter, glass panel 24 is heated and bent to the desired contour with a bending furnace or other bending apparatus, followed by tempering to strengthen the glass. Such heating, bending and tempering operations cause the ceramic paint 26 to become fused to surface 22. Thus, although starting as a layer of paint containing ceramic particles and pigment, coating 26 ends up after bending and tempering, as a thin frit layer of ceramic material, which, in actuality, is fused to surface 22 of glass panel 24. Since ceramic frit coating 26 includes a pigment of a desired colour, preferably a dark colour such as black or the like, the layer results in a permanent, second or inside surface coloration of glass panel 24. When viewed from the opposite or outer side 20, the transparent thickness of panel 24, backed up by the coloured ceramic frit layer 26, provides an appearance of depth and richness which blends well with the surrounding painted or glass areas on a vehicle. One ceramic paint used to form the opaque black ceramic frit coating 26, described above, is manufactured by the Drakenfeld Pigments Division of Ciba-Geigy Corporation located in Washington, Pennsylvania. Such paint includes small ceramic particles and a suitable metal oxide pigment suspended in oil of a type conventionally known in the art. The resulting frit layer is opaque and normally black in colour. This ceramic paint is preferably screen-coated on a predetermined portion of inner surface 20 of panel 24 using a 200-mesh screen. Ceramic particles in layer 26 are melted and fused to one another, are permanently bonded and fused to the inner glass surface 22, and form the equivalent of the glass itself in terms of strength and adherence. Fixed to ceramic frit layer 26 and spaced inwardly from peripheral edge 18 toward the centre of the panel are at least one, and preferably no more than two, mounting members 30, and at least one member 32 which cooperate to retain and articulate panel assembly 24 within window opening 14. Each mounting member 30, 32, is bonded at least 0.316 cm (0.125 in) inboard of peripheral edge 18 to panel inner surface 22 to retain panel 24 within window opening 14 without the need to extend a fastener through the sheet-like panel 24 or encapsulate the peripheral edge 18 of panel 24 with a resinous gasket extending around the panel edge on both inner and outer surfaces or the like. Described in greater detail below, the bond between mounting members 30, 32 and glass panel 24 and/or frit layer 26 is sufficient to withstand loads greater than 68 kg (150 lb), preferably greater than 113.6 kg (250 lb), and most preferably about 136 kg (300 lb), even after environmental exposure. The resulting bond is such that if failure occurs under these loads, the failure mode is other than in the adhesive bond interface between mounting members 30, 32 and panel 24. That is to say, if a failure occurs in the bond between mounting members 30, 32 and panel 24 under a load, the failure mode will be a mechanical failure of the substrate (mounting member or panel) or in the cohesion of the adhesive itself. For the purposes of this description, the adhesive bond or adhesion of the adhesive with the mounting member or panel is the ability of the adhesive to adhere to the substrate. Cohesion is the ability of the adhesive to bond with itself. In one embodiment (Figs. 4-6), each mounting member 30 is a 0.1 to 10.0 millimetre (mm) thick, and preferably 0.5 to 1.0 mm thick, spring steel hinge having an elongate flange portion 34 with one edge 36 defining an adjoining tab 38. Tab 38 is offset from the plane of flange 34 by leg 37. Tab 38 is thus bent in an S-shaped form with respect to flange 34 although the free end portion tab 38 is generally parallel to flange 34. The bends between tab 38 and flange 34, and particularly leg 37, provide a spring-like hinge, the operation of which will become readily apparent below. Hinge flange 34 may also be prestressed or bent to conform to the surface of panel 24, especially if the panel is curved. In this regard, it is desirable to have a convex curvature to the surface of hinge flange 34 that is adhesively bonded to panel surface 24. This results in not only a more uniform adhesive bond, but also evenly distributes any load along the bonding surface and economizes the amount of adhesive used. Extending through tab 38 and away from panel 24 is a stud 52, having a head 53 bonded with or welded to tab 38. The opposite end of stud 52 is to be fastened to the vehicle as explained below. Optionally, formed in flange portion 34, and extending therethrough, are a plurality of holes 40 generally aligned along the longitudinal axis of the flange. The size of each hole may range from 0.1 to 10 mm or more, but is preferably about 3.0 millimetres. In the preferred embodiment, holes 40 are spaced equidistantly with the centre points between the holes being approximately eight and one-half millimetres apart. The size and spacing of holes 40 are designed to provide optimum access of both air and moisture/humidity to permeate to an underlying adhesive described in greater detail below. The perforations also reduce the weight of each hinge, and provide a mechanical surface to bond with the adhesive and aid in bonding the hinge to the panel. Flange portion 34 also contains embossments 42 adjacent aligned holes 40 which extend from a lower surface 44 of flange 34 and serve to space flange 34 from the inner surface 22 of panel 24. In a preferred embodiment, embossments 42 extend from flange 34 by a distance on the order of 0.1 to 3.0 mm, and preferably 1.0 mm. The actual distance may vary depending on the type of adhesive used. However, this offset distance has been found to be quite adequate for the variety of adhesives described below. Holes 40 and embossments 42 may be easily formed in flange portion 34 by stamping or punching during the formation of spring hinge 30. For panel assemblies employing a single hinge 30, it is preferred that the surface area of flange 34 bonded to panel 24 be approximately between 25.8 cm 2 (4 in 2 ) and 323 cm 2 (50 in 2 ), and most preferably approximately 96.8 cm 2 (15 in 2 ). On a two-hinge system, each hinge would preferably have a bonding area approximately between 13 and 323 cm 2 (2-50 in 2 ), and most preferably on the order of 25,8 cm 2 (4 in 2 ). The aspect ratio (ratio of length to width) of each hinge, no matter whether a single hinge or dual hinge system, is preferably greater than 1 but less than 1,000, and most preferably approximately 8 to 10. Dimensions may vary depending upon the specific application. However, the hinge design is intended to provide the most bonding strength and structural stability economically and concealing the hinge in the frit area on the panel. Although hinge 30 is described as being made from spring steel, other materials may also be used such as cold rolled steel, plastics, composite materials and other materials which are capable of withstanding flexural or bending moments. These materials will become apparent to one of ordinary skill in the art. Pivot-based, non-flexure hinges could also be used to equal effect. Referring to Figs. 5 and 6, flange 34 of hinge 30 has its lower surface 44 bonded to frit layer 26 by a first and second adhesive 46 and 48, respectively. In a preferred embodiment, adhesive 48 is a temporary fixturing adhesive such as a hot-melt thermoplastic, which temporarily locates or fixtures hinge 30 against frit 26, while adhesive 46 cures and forms the permanent primary bond. Adhesive 46 may be selected from a number of adhesive classes including moisture-activated urethanes such as described in United States patent 3,707,521, moisture-activated silicones, moisture-curable activated urethanes, chemically-activated adhesives, and thermally-activated adhesives, such as shown in Table I below. Other adhesives, such as aerobically-cured, anaerobically-cured, and radiation-cured adhesives can also be used. When cured, the bond-line thickness is in the range of 1 micron to 10 mm, preferably 5 microns to 5 mm, and most preferably 25 microns to 1 mm. For large area vehicle windows where load integrity over a long surface life and through extreme climatic conditions is critical, thermosetting adhesives such as urethanes, silicones, acrylates, and epoxies are preferred over thermoplastic adhesives such as polyvinylbutyral. For moisture-activated adhesives, it is preferable that the assemblies be exposed to a high humidity atmosphere after initial bonding is achieved in order to promote rapid, complete cure of the adhesive. In this regard, it is preferable that the assemblies be exposed to a relative humidity in excess of 40 percent R.H. and preferably, in excess of 75 percent R.H. for a time period ranging from about 30 minutes to approximately 24 hours, or longer, and at a temperature range from about 15.6°C to about 121.1°C, preferably about 23.9°C to about 43.3°C. Chemically-activated adhesives can be activated by means such as catalysts, curing agents, and their equivalents as conventionally known in the adhesive arts. Activation can be promoted by heat and/or by radiation including ultraviolet radiation and microwave radiation. Thermally-activated adhesives may be activated by a variety of heating means including convective heating, infrared heating, focused infrared heating, inductive or induction heating, conductive heating, microwave heating and their equivalents. Cure of the bond joint and the assemblies can be promoted and achieved by use of ovens, high humidity chambers, conveyors, heaters and by their combination. Manufacturer Type Trade Name Essex Specialty Chemicals BetaSeal™ 57302 Moisture-activated urethane Morton Yokohama WS70-FK Moisture-activated urethane Sika Sika-Flex™ 255-FC Moisture-activated urethane Dow Corning 732 Moisture-activated silicone Dow Corning Q3-6611 Thermally-activated silicone Dow Corning X3-6265 Thermally-activated silicone 3M JetWeld™ TS-230 Moisture-curable hot melt urethane 3M Scotchweld Thermally- AF-126-2 activated modified epoxy 3M Scotchweld AF-163-2U Thermally-activated modified epoxy Dymax 625-BT Chemically-activated acrylate Ciba Geigy R 382-3 Thermally-activated modified epoxy Ciba Geigy R 609 Thermally-activated modified epoxy Dexter Adhesives EA 9628 Thermally-activated modified epoxy B.F. Goodrich PL-760 Thermally-activated modified epoxy B.F. Goodrich PL-776 Thermally-activated modified epoxy B.F. Goodrich PL-633 Thermally-activated nitrile-phenolic It is further preferred that the selected adhesive come in a single package so that no mixing of reactants need occur prior to application. The one-package adhesives provide a much more efficient method than prior adhesives requiring mixing of reactants. It is further preferred that the adhesive have a jelly-like consistency, preferably having a viscosity at 25°C greater than 5 Poise, and most preferably greater than 100 Poise, or can also be a hot-melted adhesive, or in film form for easy application. Adhesive 46 is preferably a urethane adhesive and most preferably a moisture-activated adhesive urethane such as Morton Yokohama WS70-FK, available from Morton International of Ridgewood, Illinois, although epoxies and activated adhesives may also be used. Stand-offs or embossments 42 provide a space between hinge flange 34 and the surface of frit layer 26 for adhesive 46. In addition, holes 40 extending the length of hinge flange 34 allow adhesive 46 to be extruded therethrough to provide a mechanical coupling due to the extension of adhesive over the edges of the holes 40, as well as to provide an avenue for the permeation of moisture to complete the cure of the adhesive. To improve and promote the bonding characteristics of adhesive 46 glass inner surface 22 or frit layer 26, and/or the lower surface 44 of hinge flange 34 may be coated with an adhesion-promoting compound or primer 50. These adhesion-promoting compounds generally include silanes such as available from Dow Corning, or titanium or zirconium coupling agents such as available from Kenrich Petrochemical, Inc., of Bayon, New Jersey, or equivalents, which greatly enhance the bonding ability of the adhesive to the substrate. If the primer 50 is applied to frit layer 26 or onto glass surface 22, a preferred primer is designated Morton Yokohama MS-90 available from Morton International in Ridgewood, Illinois. If primer 50 is applied to a metallic surface such as hinge flange 34, a preferred primer is Morton Yokohama RC-50, also available from Morton International. Although these two primers are preferred, they are not the only primers available which may be equally if not more suitable for the application. Although the adhesion-promoting compound 50 may be applied to frit coating 26 and to lower surface 44 of flange 34, Figs. 5 and 6 illustrate the primer compound only on frit coating 26. Adhesive 46, combined with adhesion-promoting compound or primer 50, provides a bond between frit coating 26 and hinge 30, which exceeds standards established by many U.S. automobile manufacturers for window panels. Bonding strengths will vary depending upon the bonding surface area and the types of base materials used. Based upon the materials described herein, the majority of bonds withstood straight pull tests of more than 150 pounds (68 kg) applied at a rate of 25 millimetres per minute without a failure of the cohesion or adhesion after environmental exposure. In a first embodiment of window panel assembly 12, two hinges 30, such as described above, are bonded to frit coating 26 inwardly from peripheral edge 18 and spaced from each other so as to provide generally balanced support for panel assembly 12. To locate panel assembly 12 within window opening 14, a mounting stud 52 passing through hinge flange or tab 38 is received through an opening 54 formed in a pinch weld flange 56 which defines window opening 14 (see Fig. 10). Stud 52 is then retained within hole 54 by a suitable fastener. In the alternative, stud 52 may be replaced with a self-anchoring fastener such as a Christmas-tree post or other similar fastener. Distant from hinges 30, and preferably at an opposite end of panel assembly 12, is at least one mounting member 32. See Figs. 1, 7 and 8. In a preferred embodiment, mounting member 32 is a mounting stud having a disk or circular-shaped flange 60 made from 1.0 millimetre thick, cold rolled steel. Disk 60 has a lower surface 62 which is concave, and an upper surface 64 which is convex, as a result of contours formed by several concentric rings or shoulders 78, 80, respectively, formed in disk 60. Formed in disk 60 and spaced equidistantly from each other, are a plurality of embossments 42 which define stand-offs extending from lower surface 62 of disk 60 similar to those described above. Between embossments 42, and preferably spaced equidistantly from each other, are holes or rotated lances 66 piercing disk 60. Holes or rotated lances 66 are formed from lower surface 62 through to surface 64. Rotated lances are formed in such a manner so as to produce a tag 72 inclined above each hole 66 (Fig. 8a). Extending upwardly from surface 64 through a hole 70 located generally in the centre of disk 60 is a stud 68. Stud 68 is permanently fixed to disk 60 by welding flange 74 to lower surface 62. Flange 74 of stud 68 lies substantially within the uppermost concave portion 76 of surface 62 to provide a maximum offset between stud flange 74 and panel 24. Disk 60 is bonded to panel 24 in generally the same manner as hinge 30 described above. The inner surface 22 of panel 24 may be coated with opaque frit layer 26 either in an area restricted to that for button stud 60, i.e., slightly larger than the area of lower surface 62 of disk 60, or is generally coated with the frit layer 26 as indicated by dash line 26' shown in Figs. 2 and 3. Lower surface 62 of disk 60 and frit layer coating 26 are preferably coated with the desired adhesion-promoting primer compound 50 as described above. The central portion of concave surface 62 of disk 60 is permanently bonded to frit layer 26 by adhesive 46 while the peripheral edge of surface 62 is temporarily fixtured to frit layer 26 by a thermoplastic hot-melt or other adhesive 48. Moreover, permanent adhesive 46 mechanically bonds disk 60 to frit layer 26 by a portion of adhesive 46 extruded through holes or rotated lances 66. In the case of rotated lances, extrusion of adhesive 46 is minimized by tab or vane 72 partially damming or restricting flow of adhesive 46 through each rotated lance 66. Embossments or stand-offs 42 extending from lower surface 62 provide a space between panel surface 22 or frit layer 26 and disk 60. Mounting stud or disk 60 is fitted with an appropriate latching of actuating mechanism (not shown) which is attached to the inside of window opening 14 and which is used to actuate window assembly 12 between the open and closed positions via hinges 30. Such actuators include overcentre hinges, as well as pneumatic, electric or cable actuators. In the alternative to centrally locating adhesive 46 between disk 60 and frit layer 26 as shown in Fig. 8, thermoplastic adhesive 48 may be located below stud flange 74 while a bead of adhesive 46 is placed thereabout. Fixturing of disk 60 is still obtained by the thermoplastic hot-melt or other adhesive 48 located in a central portion of disk 60, while the primary adhesive 46 is then forced outwardly toward the peripheral edges of disk 60 to provide the maximum bonding surface area. In yet another alternative, fixturing adhesive 48 may be omitted and both hinge 30 and mounting member 60 may be mechanically fixtured on panel 24 while the primary adhesive 46 cures. Examples of mechanical fixturing include gravity, mechanical locating, pressing or clamping including robotic, and manual locating, pressing or clamping. A preferred embodiment of the invention includes hinge 130, shown in Figs. 13-15, made from 1.0 millimetre thick, cold-rolled, half-hardened, epoxy E-coated steel in a U-shape such that tab portion 138 overlies and is parallel to elongate flange portion 134. It is preferred that the grain of the steel be oriented generally perpendicular to the axis of the arcuate, U-shaped bend. Leg 137 interconnecting flange 134 and tab 138 is arcuate to provide the spring-like hinge action. Flange 134 contains a plurality of holes 140 which are generally aligned along the longitudinal axis of the flange at equidistantly spaced intervals, preferably approximately 8.5 millimetres. Moreover, the preferred diameter of each hole 140 is about 3.0 millimetres. Flange 134 also contains embossments 142 which extend from lower surface 144 and serve to space flange 134 from panel inner surface 122. Preferably, embossments 142 extend approximately 1 millimetre from flange 134. As shown in Fig. 14, the outer ends of flange 134 may curve slightly upwardly before attachment to panel 24'. Such ends are pressed down against panel 24' when fixtured or secured to the panel. Flange 134 also includes a large hole 143 located directly opposite the portion of tab 138 which receives stud 152. Hole 143 is provided to allow stud 152 to be placed through tab 138 so that stud head 153 can be welded or bonded to tab 138. The opposite end of stud 152 extending from tab 138 is to be fastened to the vehicle as described below. As shown in Fig. 14, hinge 130 is curved and preferably applied to panel 24' in a manner similar to that described for hinge 30 on panel 24. Panel surface 22' preferably includes a primer 50' corresponding to primer 50 and adhesives 46', 48' may be used in the same manner as adhesives 46, 48 for hinge 30. Window assembly 12 may also include a gasket 13 (Figs. 3 and 9) mounted to inner surface 22 or to pinch weld flange 56 to seal window assembly 12 in the window opening 14 when panel 24 is in the closed position. A variety of seals may be used including a bubble seal. In manufacturing window assembly 12, hinges 30, 130 and disk 60 are preferably cleaned with isopropyl alcohol to remove any dirt and debris. The isopropyl alcohol is also used to clean the glass surface and/or frit coating 26 which will receive hinges 30, 130 and disk 60. After cleaning of the surfaces, panel surface 22 and/or frit coating 26 receive adhesion-promoting primer compound 50 which is then allowed to dry. Optionally, while adhesion-promoting primer compound 50 on panel 24 is drying, the appropriate primer 50 may also be applied to bottom surface 44 of hinges 30, 130 and to lower surface 62 of disk 60 and allowed to dry. Primer 50 may be applied to hinges 30, 130 and disk 60 in a variety of ways, including using a dauber, a wipe, spray or other applicator. In a preferred embodiment, primer 50 is applied to hinges 30, 130 and disk 60 in one direction with a dauber wipe to obtain as uniform a coat as possible. If any bare spots appear after the initial cure time, another coat of primer 50 may be applied in the same direction. Automated systems such as robotic or conveyor systems may be used to carry out the application. Once primer 50 has dried, the preferred urethane adhesive 46 is applied in a bead to hinges 30, 130 and disk 60. For single-piece application, adhesive 46 may be applied using a glue gun, caulking gun or similar applicator. For multi-piece applications, robotic or conveyor applicators would be more appropriate. Sufficient room is provided on hinges 30, 130 and disk 60 to receive the hot melt or thermoplastic fixturing adhesive 48 which may be applied using any of the above techniques. Soon after thermoplastic adhesive 48 is applied to mounting members 30, 32, 130, they are located on and engaged with the surface 22 of panel 24 overlying the frit coating 26. It is preferred that each mounting member 30, 32, 130 be temporarily held in place at least until thermoplastic fixturing adhesive 48 has set. If fixturing adhesive 48 is not used, mounting member 30, 32, 130 most likely will need to remain still relative to panel 24 for a longer period until bonding adhesive 46 cures. As mentioned above, this may be achieved by gravity, manual, or mechanical means. Each panel assembly 12 is then placed in a chamber where the assemblies are preferably cured at a temperature of approximately 90°F and a relative humidity greater than 85 percent. The holes extending through flange 34 of hinge 30, and through disk 60 allow the moisture in the curing chamber to permeate adhesive 46 which results in a net decrease in curing time. It has been found that a cure time of about six hours for flanges without holes can be decreased to about four hours for flanges with holes. Following the cure time in the chamber, the finished panel assemblies 12 are then ready for shipment to the vehicle manufacturer. It is preferred that a moisture-activated urethane adhesive be used. Window panel assemblies manufactured using the moisture-activated Morton Yokohama WS70-FK urethane adhesive, and the Morton Yokohama MS-90 and RC-50 primers, resulted in bonds between the mounting members and panels which withstood straight pull test tensional load greater than 113.3kg (250lb), and a vast majority withstood loads greater than 136kg (300lb). In at least two instances, the bonds withstood tensional loads on the order of 181.3kg (400lb). Other tests were conducted on the window assemblies which included thermal cycle tests, water immersion (80°C) for 100 and 240 hours, vibration tests, CASS, and impact tests. In general, the bonds between the mounting members and panel withstood loads, on average, greater than 102kg (225lb) while loads greater than 113kg (250lb) were achieved on average for panels subjected to immersion in 80°C water for 100 and 240 hours. Similar or better results were achieved on samples subjected to vibration, CASS and impact tests. Similar results can be achieved using the family or classes of adhesives described above.

Claims: A flush mounted hinged window panel assembly for a vehicle adapted to be mounted in a window opening of the vehicle and comprising a panel including a transparent sheet having an inner surface (22) and an outer surface (20) terminating in a peripheral edge defining a shape to fit within the window opening such that the outer surface (20) of the sheet is generally flush with the exterior surface of the vehicle adjacent the opening; and at least one window mounting member (30) bonded to said inner surface (22) of said sheet at a position spaced inwardly from the peripheral edge for securing the sheet in the window opening, the window mounting member having a flange (34) attached to the inner surface (22) of the sheet; characterised in that said assembly includes an adhesive (46) between said inner surface (22) of the sheet and said flange (34) providing a bond between the flange of the window mounting member and the inner surface (22) of the sheet such that said sheet and window-mounting member are held together in such a manner so as to withstand a straight pull test of more than 68kg (150lb), said window panel having an area greater than 1613 cm 2 (250in 2 ). A flush-mounted hinged window panel assembly as defined in claim 1, wherein the flange (34) includes a plurality of perforations (40) extending therethrough. A flush-mounted hinged window panel assembly as defined in claim 2, wherein the perforations (40) in the flange of the mounting member include vanes (72) for controlling a flow of the adhesive for bonding the mounting member to the inner surface (22) of the sheet when the mounting member is located with respect to the panel. A flush-mounted hinged window panel assembly as defined in claim 1, further including an opaque coating between the inner surface (22) of the sheet and the adhesive bonding the mounting member to the panel. A flush-mounted hinged window panel assembly as defined in claim 4, wherein said transparent sheet is formed from glass, said assembly further including an adhesion-promoting compound between the opaque coating and the adhesive bonding the mounting member to the glass sheet. A flush-mounted hinged window panel assembly as defined in any of claims 1 to 5, wherein the adhesive includes: a first adhesive having a first cure/set time for fixing the mounting member on the inner surface of the sheet; and a second adhesive adjacent the first adhesive and having a second cure/set time greater than the first cure/set time for bonding the mounting member to the inner surface (22) of the sheet. A flush-mounted hinged window panel assembly as defined in any of claims 1 to 6, wherein the mounting member includes a second portion extending from the flange to engage a fixed substrate. A flush-mounted hinged window panel assembly as defined in any of claims 1 to 7, further including a plurality of spacing means for spacing the flange (34) from the inner surface of the sheet. A flush-mounted hinged window panel assembly as defined in any of claims 1 to 7, wherein the mounting member includes a latch mount having a flange bonded to the inner surface (22) of the sheet with said same adhesive bonding the mounting member to the panel, the latch mount having an actuating portion extending therefrom to engage a fixed substrate. A flush-mounted hinged window panel assembly as defined in claim 9, wherein the latch mount further includes a circular flange embossed to define a plurality of standoffs for spacing the flange from the inner surface (22) of the sheet. A flush-mounted hinged window panel assembly as defined in claim 9 or 10, wherein the latch mount further includes a plurality of holes lanced therein and spaced generally equidistantly from each other to direct a flow of adhesive between the flange and the inner surface (22) of the sheet. A flush-mounted hinged window panel assembly as defined in any of claims 1 to 11, further including an adhesion-promoting compound between the mounting member and the adhesive bonding the mounting member to the panel. A flush-mounted hinged window panel assembly as defined in any of claims 1 to 12, wherein the adhesive includes an activated adhesive. A flush-mounted hinged window panel assembly as defined in any of claims 1 to 11, wherein the adhesive is selected from the group consisting essentially of: moisture-activated adhesives, thermally-activated adhesives, chemically-activated adhesives, aerobically-cured adhesives, anaerobically-cured adhesives, and radiation-cured adhesives. A flush-mounted hinged window panel assembly as defined in claim 1, wherein the bond of the mounting member to the inner surface (22) of the sheet is sufficiently strong to withstand said straight pull test of about 68kg (150lb) at a rate greater than about 25 millimetres per minute. A flush-mounted hinged window panel assembly as defined in claim 13, wherein said pull test was performed after soaking the panel assembly in 180°C water for at least 100 hours. A flush-mounted hinged window panel assembly as defined in claim 5, wherein the adhesion-promoting compound includes at least one coupling agent selected from the group Comprising a silane, titanium and zirconium coupling agent. A flush-mounted hinged window panel assembly as defined in claim 1, further including an adhesion-promoting compound applied to at least one of said inner surface (22) of said sheet and said window-mounting member. A flush-mounted hinged window panel assembly as defined in claim 6, wherein said second cure/set time of the second adhesive is greater than the first cure/set time of said first adhesive. A flush-mounted hinged window panel assembly as defined in any of claims 1 to 19, wherein said at least one mounting member includes at least one hinge member. A flush-mounted hinged window panel assembly as defined in claim 20, wherein the hinge member includes: a flange portion having a longitudinal axis and a plurality of holes extending therethrough; a spring member laterally offset and extending from the flange portion; and a mounting stud extending through the spring member for attaching the hinge member to the vehicle. A flush-mounted hinged window panel assembly as defined in claim 1, wherein said at least one mounting member is articulated. A flush-mounted hinged window panel assembly as defined in any of claims 1 to 22, wherein the flange of the mounting member occupies approximately between 0.5 percent and 2.0 percent of a surface area of the inner surface (22) of the sheet. A flush-mounted hinged window panel assembly as defined in claim 22, wherein the articulated mounting member has an aspect ratio approximately between 1 and 1000, for example 5 and 25 or more particularly 8 and 10. A flush-mounted hinged window panel assembly as defined in claim 10, wherein the standoffs have a thickness within the range of 0.1 and 3.0 millimetres. A flush-mounted hinged window panel assembly as defined in any of claims 1 to 25, wherein the flange of the at least one mounting member conforms to the inner surface (22) of the sheet. A flush-mounted hinged window panel assembly as defined in any of claims 1 to 26, wherein the flange of said at least one mounting member has a thickness within the range of 0.1 and 10.0 millimetre, for example 0.5 and 1.0 mm.

Inventors: REPP ROBERT S, STALLMAN PAMELA M, REPP, ROBERT S., STALLMAN, PAMELA M.
Applicants: DONNELLY CORP, DONNELLY CORPORATION
Application year: 1994
Main classification: B60J1
IPC codes: B60J1